The present invention relates to a vehicle airbag that is inflated by inflation gas when an impact is applied to a vehicle such as an automobile, thereby protecting an occupant seated in a vehicle seat.
When an impact is applied to an automobile due to, for example, a frontal collision, the upper body of the occupant seated in the automobile seat acts to lean forward due to inertia. To deal with such a situation, an automobile airbag apparatus is effective that inflates an airbag in front of the occupant to protect the occupant from the impact.
Japanese Laid-Open Patent Publication No. 2-303951 discloses an automobile airbag used in such an automobile airbag apparatus. The airbag of the publication includes an airbag main body and auxiliary airbag portion. The airbag main body is a main part of the automobile airbag that is inflated in front of the occupant in response to an impact to the vehicle to restrict the forward leaning of the upper body of the occupant. The auxiliary airbag portion is inflated to project rearward from at least a part of the airbag main body, specifically, from a part that is close to a side wall portion with respect to the widthwise direction of an automobile seat, thereby restricting the sideways move of the occupant.
However, if the automobile receives a frontal and oblique impact, the automobile airbag of Japanese Laid-Open Patent Publication No. 2-303951 can cause the following problems.
That is, such an impact causes the upper body of the occupant to lean obliquely forward due to inertia. The airbag main body and the auxiliary airbag portion receive the load of the leaning occupant. However, in the above described automobile airbag, the part of the airbag main body and the auxiliary airbag portion that receives the load of the occupant cannot maintain the original shape, but may be deformed obliquely forward or sideways. Further, after contacting the automobile airbag, the head of the leaning occupant can rotate about the neck.